Compositions and methods for ruthenium and tantalum barrier cmp

Abstract

This invention provides a chemical-mechanical polishing composition comprising an abrasive, an aqueous carrier, an oxidizing agent having a standard reduction potential of greater than 0.7 V and less than 1.3 V relative to a standard hydrogen electrode, and optionally a source of borate anions, with the proviso that when the oxidizing agent comprises a peroxide other than perborate, perphosphate, or percarbonate, the chemical-mechanical polishing composition further comprises a source of borate anions, wherein the pH of the chemical-mechanical polishing composition is between about 7 and about 12. The invention also provides a method of polishing a substrate with the aforementioned chemical-mechanical polishing composition.

1 . A chemical-mechanical polishing composition comprising:
 (a) an abrasive,   (b) an aqueous carrier,   (c) an oxidizing agent having a standard reduction potential of greater than 0.7 V and less than 1.3 V relative to a standard hydrogen electrode, and   (d) optionally a source of borate anions, with the proviso that when the oxidizing agent comprises a peroxide other than perborate, percarbonate, or perphosphate, the chemical-mechanical polishing composition further comprises a source of borate anions,   
     wherein the pH of the chemical-mechanical polishing composition is between about 7 and about 12. 
   
   
       2 . The chemical-mechanical polishing composition of  claim 1 , wherein the oxidizing agent oxidizes ruthenium to the +3 oxidation state. 
   
   
       3 . The chemical-mechanical polishing composition of  claim 1 , wherein the oxidizing agent oxidizes ruthenium to the +4 oxidation state. 
   
   
       4 . The chemical-mechanical polishing composition of  claim 1 , wherein the oxidizing agent comprises perborate, percarbonate, perphosphate, hydrogen peroxide, or combinations thereof. 
   
   
       5 . The chemical-mechanical polishing composition of  claim 4 , further comprising a source of borate anions. 
   
   
       6 . The chemical-mechanical polishing composition of  claim 1 , wherein the oxidizing agent is present in the chemical-mechanical polishing composition at a concentration of about 0.05 wt. % to about 10 wt. %. 
   
   
       7 . The chemical-mechanical polishing composition of  claim 1 , further comprising an ammonia derivative selected from the group consisting of ammonium-containing compounds, hydroxylamines, methylamines, and combinations thereof. 
   
   
       8 . The chemical-mechanical polishing composition of  claim 7 , wherein the ammonia derivative is present in the chemical-mechanical polishing composition at a concentration of about 0.01 wt. % to about 2 wt. %. 
   
   
       9 . The chemical-mechanical polishing composition of  claim 1 , wherein the abrasive is a metal oxide selected from the group consisting of alumina, silica, ceria, zirconia, titania, germania, and combinations thereof. 
   
   
       10 . The chemical-mechanical polishing composition of  claim 9 , wherein the metal oxide abrasive is silica. 
   
   
       11 . The chemical-mechanical polishing composition of  claim 1 , wherein the oxidizing agent comprises perborate. 
   
   
       12 . A method of polishing a substrate comprising:
 (i) providing a substrate;   (ii) providing a chemical-mechanical polishing composition comprising:
 (a) an abrasive, 
 (b) an aqueous carrier, 
 (c) an oxidizing agent having a standard reduction potential of greater than 0.7 V and less than 1.3 V relative to a standard hydrogen electrode, and 
 (d) optionally a source of borate anions, with the proviso that when the oxidizing agent comprises a peroxide other than perborate, percarbonate, or perphosphate, the chemical-mechanical polishing composition further comprises a source of borate anions, 
    wherein the pH of the chemical-mechanical polishing composition is between about 7 and about 12;   (iii) contacting the substrate with a polishing pad and the chemical-mechanical polishing composition; and   (iv) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the surface of the substrate to polish the substrate.   
   
   
       13 . The method of  claim 12 , wherein the substrate comprises ruthenium, tantalum, copper, TEOS, or a combination thereof, and at least a portion of the substrate is abraded to polish the substrate. 
   
   
       14 . The method of  claim 13 , wherein the substrate comprises ruthenium, and at least a portion of the ruthenium is abraded to polish the substrate. 
   
   
       15 . The method of  claim 12 , wherein the oxidizing agent oxidizes ruthenium to the +3 oxidation state. 
   
   
       16 . The method of  claim 12 , wherein the oxidizing agent oxidizes ruthenium to the +4 oxidation state. 
   
   
       17 . The method of  claim 12 , wherein the oxidizing agent comprises perborate, percarbonate, perphosphate, hydrogen peroxide, or combinations thereof. 
   
   
       18 . The method of  claim 12 , wherein the oxidizing agent is present in the chemical-mechanical polishing composition at a concentration of about 0.05 wt. % to about 10 wt. %. 
   
   
       19 . The method of  claim 17 , wherein the oxidizing agent is selected from the group consisting of potassium perborate, sodium perborate monohydrate, and combinations thereof. 
   
   
       20 . The method of  claim 17 , wherein the oxidizing agent is hydrogen peroxide and wherein the chemical-mechanical polishing composition further comprises a source of borate anions selected from the group consisting of potassium tetraborate tetrahydrate, ammonium biborate tetrahydrate, and combinations thereof. 
   
   
       21 . The method of  claim 12 , wherein the chemical-mechanical polishing composition further comprises an ammonia derivative selected from the group consisting of ammonium-containing compounds, hydroxylamines, methylamines, and combinations thereof. 
   
   
       22 . The method of  claim 21 , wherein the ammonia derivative is present in the chemical-mechanical polishing composition at a concentration of about 0.01 wt. % to about 2 wt. %. 
   
   
       23 . The method of  claim 21 , wherein the ammonia derivative reduces the open-circuit potential of ruthenium by about 0.1 V to about 0.3 V relative to a standard hydrogen electrode. 
   
   
       24 . The method of  claim 12 , wherein the abrasive is a metal oxide selected from the group consisting of alumina, silica, ceria, zirconia, titania, germania, and combinations thereof. 
   
   
       25 . The method of  claim 24 , wherein the metal oxide abrasive is silica.